1. Field of the Invention
This invention relates to an apparatus and method for automatically creating membership functions.
2. Description of the Related Art
In a conventional method of setting membership functions, first an input variable (characteristic axis) suitable for executing fuzzy reasoning is selected and then the user creates a membership function from a distribution of input values relating to this input variable.
With such a conventional method of setting a membership function, however, the membership function cannot be created unless the user is a skilled individual or a technician possessing adequate knowledge. This means that the general user cannot utilize a fuzzy reasoning apparatus or finds the apparatus difficult to use. In particular, in view of the fact that input-variable selection is difficult, it is also difficult to obtain a distribution of input data serving as the basis of a membership function.
For example, in a case where "tastiness" is evaluated, whether sweetness alone should be the input variable (characteristic axis), whether other factors such as color and water content should also be considered, and the relationship between tastiness and sweetness, color and moisture often are entirely unknown.